Elastomeric materials have been formed into countless different articles suitable for use in many applications, such as surgical gloves, examining gloves, condoms, catheters, balloons, tubing, and the like. Elastomeric materials have been found particularly suitable for such applications due to their physical characteristics. For example, elastomeric materials, in addition to having good elastic properties, exhibit good strength characteristics and may be produced so as to be impermeable not only to aqueous solutions, but also to many solvents and oils.
Elastomeric materials are typically tacky to the touch and present a somewhat sticky surface. Tackiness of the surface of the article often renders manufacture and use of the article difficult, at best. For example articles such as gloves, catheters, or balloons may stick to formers during manufacture and to themselves and each other (commonly termed xe2x80x9cblockingxe2x80x9d) during packaging and shipping. In addition, elastomeric articles often feel sticky to human skin. For example, elastomeric articles such as gloves may be difficult to slip over the hand during donning due to tackiness at the glove surface.
Several methods have been developed in the past for decreasing surface tack of an elastomeric article. For example, one common process has been the addition of a powder, such as talc or calcium carbonate powder, for example, to the article""s surface. The powder acts as a buffer or barrier between the surface of the article and the skin to make the elastomeric article more slippery. While powder on the article surface is acceptable for some applications, powders may not be desired in certain applications, such as surgical or other clean-room type applications.
As a result, powder free coatings have been developed in an attempt to decrease surface friction of the elastomeric articles. For example, a variety of polymeric coatings have been developed for elastomeric articles in an attempt to provide the articles with increased slip at the surface. For instance, hydrophilic coatings, such as hydrophilic hydrogel polymer coatings, have been used in an attempt to increase damp donning performance.
Other processes used in the past for increasing surface slip include altering the surface of the elastomeric article itself. For example, components have been grafted to the surface of the elastomeric article in an attempt to improve slip characteristics of the article. U.S. Pat. No. 4,595,632 to Mayhan, et al., which is incorporated herein by reference thereto as to all relevant matter, discloses a process for forming elastomeric articles including a grafted fluorocarbon on the surface.
Some of these methods, while improving surface slip characteristics of elastomeric articles with respect to dry surfaces, have not similarly improved the slip characteristics of the articles with respect to damp surfaces. More specifically, when the treated surface becomes damp, the coefficient of friction increases, and the article, such as the glove, for example, becomes difficult to slip over the skin.
The damp slip characteristics of an elastomeric article may be particularly important in medical applications. For example, catheters must often have the ability to slide across damp internal epithelial tissue. Similarly, medical gloves are usually donned after the hands have been washed without complete drying, so that the hands may be quite damp while the wearer is attempting to slide the gloves over the skin.
A variety of lubricants have been developed in an attempt to alleviate the problems of damp slip characteristics in these articles. Exemplary lubricants used include, for example, silicone lubricants, surfactant lubricants, and fatty amine lubricants.
Though application of such lubricants has improved damp slip characteristics somewhat, a great deal of room for improvement still exists, and there remains a need in the art for elastomeric articles which exhibit good slip characteristics under damp conditions as well as exhibiting other characteristics desired in an elastomeric article.
In one embodiment, the present invention is directed to an elastomeric article, such as a glove, which includes a primary matrix with an elastomeric polymer at a surface. This surface of the primary matrix includes a fluorocarbon functional group grafted to the elastomeric polymer. The fluorocarbon may be grafted to the polymer backbone with an ester linkage. In addition, the article includes a silicone lubricant applied to the surface of the article having the fluorocarbon graft. In one embodiment, the lubricant may comprise a hydrophilic modified silicone. In one embodiment, the lubricant may comprise a hydrophilic amino modified silicone.
The present invention is also directed to a method for forming the elastomeric articles. In general, the method includes forming a primary matrix with an elastomeric polymer on a former. A fluorocarbon is then grafted to the polymer backbone of the elastomeric polymer with an ester linkage. A modified silicone lubricant is applied to the same surface of the article to which the fluorocarbon has been grafted. When the silicone lubricant is applied to the article surface, a bond may be formed between the modified silicone lubricant and the fluorocarbon.